1. Field of the Invention
The present invention relates to a polygonal mirror assembly having an improved structure capable of absorbing vibration generated by a polygonal mirror which rotates to deflectingly scan incident light beams, a laser scanning unit for a printer adopting the same, and a printer.
2. Description of the Related Art
A general electrophotographic printer includes a photoreceptor medium such as a photoreceptor belt which rotates along a predetermined path by a driving source, a developing unit for forming an image on an electrostatic latent image area formed on the photoreceptor medium, a transcribing unit for transcribing an image formed on the electrostatic latent image area to paper, and a laser scanning unit (LSU) for scanning laser light onto the photoreceptor medium to form an electrostatic latent image.
The laser scanning unit includes an optical source for irradiating light, an optical means for converting the scanning direction of light toward the photoreceptor medium, and a polygonal mirror assembly for deflecting light emitted from the optical source toward the optical means.
The polygonal mirror assembly includes a motor, and a polygonal mirror having a plurality of reflective facets formed on the side surface to reflect light, emitted from the optical source while the polygonal mirror is rotated by the motor, to the optical means.
However, in the conventional polygonal mirror assembly having such a configuration, it is not possible to precisely meet the center of mass and the center of rotation of the polygonal mirror on the same axis, thus resulting in vibration due to rotation of the polygonal mirror. The polygonal mirror shakes in the radial direction with the vibration, consequently deteriorating the linearity of a scan line scanned from the polygonal mirror. This deterioration of the linearity affects the quality of printing.